1. Field of the Invention
This invention relates to a pneumatic tire, and more particularly to an improvement of a bead portion structure in a heavy duty pneumatic radial tire capable of effectively preventing the pulling-out of carcass ply cord, occurrence of separation failure at turnup portion of carcass ply and the like to improve the durability. Further, it relates to a method of manufacturing such a pneumatic tire as well as a carcass band bending apparatus used therefor and a tire manufacturing apparatus.
2. Description of Related Art
In the conventional heavy duty pneumatic radial tire, the carcass ply is toroidally extended between a pair of bead cores in bead portions and turned up around the bead core from an inside of the tire toward an outside thereof in a radial direction and the resulting turnup portion is embedded and fixed in rubber in order to prevent the pulling-out of the carcass ply cord during the running of the tire under loading.
FIGS. 1a and 1b show diagrammatically section views of typical embodiments of the bead portion in the conventional heavy duty pneumatic radial tire, respectively. In the illustrated embodiment of FIG. 1a, an outer end of a turnup portion 1a of a carcass ply 1 wound around a bead core 3 is located outward from an outer end of a wire chafer 2 in a radial direction of the tire. In the illustrated embodiment of FIG. 1b, the outer end of the wire chafer 2 is located outward from the outer end of the turnup portion 1a of the carcass ply 1 in the radial direction. Moreover, numeral 4 is a bead filler.
In such conventional bead portion structures, however, the difference of stiffness is produced between inside and outside in the radial direction of the tire on the border of the position of the outer turnup end of the carcass ply 1 or the outer end of the wire chafer 2, a zone ranging from the bead portion to the sidewall portion is subjected to repetitive deformation during the running of the tire under loading, whereby stress is concentrated at each of the outer ends and in the vicinity thereof and hence it is apt to cause separation failure at the outer end from rubber, which results in the occurrence of crack cr in the bead portion as shown in FIGS. 2a and 2b. 
In order to mitigate stress produced at the outer turnup end of the carcass ply 1 or the outer end of the wire chafer 2 and in the vicinity thereof and enhance the stiffness of the bead portion to control the deformation of the bead portion, therefore, there are proposed a method wherein plural organic fiber cord layers (not shown) are circumscribed with the wire chafer 2 around the bead core 3 so as to cover the outer turnup end of the carcass ply 1 or the outer end of the wire chafer 2, a method of increasing an amount of the bead filler 4, particularly hard rubber filler arranged at the outside of the bead core 3 between a main body of the carcass ply 1 and the turnup portion thereof in the radial direction, and the like. According to these methods, however, the heat generating temperature of the bead portion becomes more higher during the running of the tire under loading, which results in the occurrence of separation failure even at the outer end of the organic fiber cord layer in addition to the above separation failure, and also the tire weight is undesirably increased to lower the productivity of the tire.
When the heavy duty pneumatic radial tire is used several times by recapping after the wearing, there is a further problem that it is impossible to use the tire due to the occurrence of separation failure around the turnup end of the carcass ply subjected to stress concentration in the use over a long time.
As a countermeasure for solving such a problem, there is a technique that the rubber gauge of the bead portion is reduced by forming a recess portion in an outer profile of the bead portion at the radial section of the tire to lower the heat build-up of the bead portion (for example, JP-A-57-191104). In this technique, however, the rubber gauge of the bead portion can not be reduced too much owing to the presence of the turnup portion of the carcass ply, so that the effect of improving the bead portion durability can not be said to be sufficient.
Furthermore, JP-A-10-193924 proposes a technique that the thickness of the bead portion is decreased by extending the turnup portion along the main body of the carcass ply to form a recess portion in the outer profile of the bead portion. In this case, however, shearing strain is caused in an interface between the main body and the turnup portion of the carcass ply is increased by the shearing deformation based on the pushing from the rim flange under loading as the rubber gauge at the outside of the turnup portion is decreased and hence there is caused a problem that separation failure is caused between the carcass ply and rubber located at the outside thereof.
In any case, it is insufficient to prevent the separation failure in the bead portion even by these conventional techniques because the service conditions of the large-size pneumatic radial tire become recently severer with the increase of the recapping number from viewpoints of environmental consideration and economical merit and the bead portion durability is degraded in lower section-profile tires recently used, and hence basic solution for bead portion troubles are not yet obtained.
In the manufacture of the tire as mentioned above, when the winding of the turnup portion of the carcass ply around the peripheral surface of the bead core is carried out by subjecting the ply cords and hence the carcass ply to elastic deformation in the winding direction with, for example, well-known bladder, blade, roll and the like and then sticking the elastic deformed turnup portion onto the peripheral surface of the bead core with rubber, it is difficult to wind the ply cords onto the peripheral surface of the bead core with a high accuracy as is expected. And also, ply cords having a large elastic restoring force such as steel cords, aromatic polyamide cords and so on can not accurately be maintained at the required winding position irrespectively of the ply cord having a small elastic restoring force. In any case, there is a problem that the pulling-out of the ply cord and the separation failure at the turnup end of the carcass ply can not sufficiently be prevented, respectively.
It is, therefore, an object of the invention to solve the aforementioned problems of the conventional techniques and to provide pneumatic tired, particularly heavy duty pneumatic radial tires capable of effectively preventing the separation failure at outer ends of the carcass ply and wire chafer from rubber and the pulling-out of the carcass ply cord to largely improve the bead portion durability without the increase of the tire weight, the degradation of the tire productivity and the like.
It is another object of the invention to provide a method for the manufacture of the pneumatic tire capable of accurately winding the turnup portion of the carcass ply onto the peripheral surface of the bead core as is expected and surely maintaining the wound posture even when using the ply cord having a large elastic restoring force as well as a carcass band bending apparatus used therefor and a tire manufacturing apparatus.
According to a first aspect of the invention, there is the provision of in a pneumatic tire comprising a carcass comprised of at least one carcass ply containing a steel cord(s) arranged at a cord angle of 70-90xc2x0 with respect to an equatorial plane of the tire and toroidally extending between a pair of bead cores and turned up around the bead core inward or outward in a radial direction to form a turnup portion, the improvement wherein a wrap part wrapping on a peripheral face of the bead core therealong is formed in the turnup portion of the carcass ply.
In the invention, there are a case that the turnup portion is formed by winding the carcass ply from an inside toward an outside in a widthwise direction of the tire, and a case that the turnup portion is formed by winding the carcass ply from an outside toward an inside in the widthwise direction of the tire.
And also, the carcass ply includes a case that many steel cords are substantially radially arranged side by side, and a case that a single steel cord is turned at a position corresponding to the turnup portion of the carcass ply and extended at a detoured state in the circumferential direction of the tire.
In the pneumatic tire according to the invention, the wrap part wrapping along the peripheral face of the bead core is formed in the turnup portion of the carcass ply, whereby the pulling-out of the carcass ply cord can effectively be prevented without prolonging the turnup portion outward in the radial direction of the tire. And also, the wrap part is located sufficiently adjacent to the bead core having a high stiffness, so that the deformation of a zone in the vicinity of the wrap part during the running of the tire under loading is effectively restrained by the bead core, a rim supporting the bead portion and the like. As a result, there is no fear of concentrating stress in the wrap part and its neighborhood due to the above deformation and hence separation failure at the wrap part and hence the turnup portion is effectively prevented.
In such a tire, at least one plastic deformation region is formed in the wrap part. Such a plastic deformation region can be realized, for example, by providing the wrap part with at least one bent or formed zone of rectangle, curve or the like adaptable to a radially sectional profile shape of the bead core. Since the wrap part is located nearer to the peripheral face of the bead core and more accurately followed thereto by the plastic deformation region, the wrap part can more effectively be restrained by the bead core to further effectively prevent the pulling-out of the carcass ply cord and separation failure of the turnup portion.
The plastic deformation region is preferable to be previously formed in a portion of the carcass ply corresponding to the warp part prior to the winding of the carcass ply around the bead core. Thus, the plastic deformation can always and accurately be conducted as it is expected and hence the above effect can be more enhanced.
In a preferable embodiment of the first aspect of the invention, at least the wrap part of the turnup portion is interposed between the bead core and a bead filler, whereby the wrap part can be closed to the bead core through the bead filler to more advantageously prevent the pulling-out of the carcass ply cord and separation failure of the wrap part.
In another preferable embodiment of the first aspect of the invention, the wrap part is extended along the peripheral face of the bead core over a half periphery of the sectional profile of the bead core. In general, the bead core has a polygonal shape, a circular shape or the like as the radially sectional profile. In any shapes, the aforementioned effect can be more enhanced by extending the wrap part along the bead core over the half periphery of the sectional profile.
In the other preferable embodiment of the first aspect of the invention, an outer end of the turnup portion is located inward from an outer circumferential edge of the bead portion at the contact region with the rim flange in the radial direction of the tire. The term xe2x80x9ccontact region of the bead portion with the rim flangexe2x80x9d used herein means a maximum contact region of the bead portion with the rim flange during the running of the tire at a maximum air pressure under a maximum load.
Thus, when the turnup portion has an outer end region protruding outward from the end of the wrap part in the radial direction, the outer end is strongly held by the rim and can be located in a zone having a very little deformation during the running of the tire under loading, whereby the concentration of stress in the outer end and the neighborhood thereof can effectively be prevented to sufficiently protect the outer end region of the turnup portion against the separation failure.
Particularly, this becomes conspicuous when the end of the wrap part is located inside in the radial direction over a position corresponding to an outer peripheral edge of the bead core embedded in the bead portion at a state of mounting onto the rim in the inflation under the maximum air pressure so as to make longer than a length of the wrap part along the bead core.
Moreover, the above features are particularly effective in pneumatic tires having an aspect ratio of not more than 60%. That is, in the tire having a small aspect ratio, shearing strain in the circumferential direction occupies a large weight rather than compression strain produced in the turnup end of the carcass ply due to the occurrence of internal stress accompanied with the bending deformation of the sidewall portion during the running of the tire under loading as a cause of creating separation failure of the turnup portion, but in the tire according to the invention, the turnup portion is wrapped so as to locate an end of the wrap part in the vicinity of the bead core having a less deformation, whereby the end of the turnup portion is worked together with the main body of the carcass ply and hence shearing strain in the circumferential direction to road surface can advantageously be reduced.
In the first aspect of the invention, it is favorable that the steel cord as the carcass ply cord has a tenacity of 80-300 kgf, preferably 100-180 kgf. When the tenacity is less than 80 kgf, it is difficult to ensure a given tenacity when the carcass ply cord is subjected to plastic deformation to decrease the tenacity by about 10-20%, while when it exceeds 300 kgf, the diameter of the cord becomes too thick and the plastic deformation becomes difficult and it is apt to create injury in the cord through the plastic deformation.
Even in the above tire, it is sometimes apt to cause a permanent set in fatigue of the bead portion, which may cause the cracking at the outside of the bead portion in the recapping or separation failure at a chafer member and hence the bead portion durability may not sufficiently be improved.
Therefore, the inventors have considered that the permanent set of the bead portion can be controlled by taking means for reducing a contact pressure between the bead portion of the tire and the rim when the tire is changed from deflate state to an inflate state and made various studies. As a result, it has been confirmed that the change of a profile of a carcass line located in a region of the bead portion outward from a contact region with a rim flange in the radial direction of the tire is made small when the tire is changed from the deflate state to the inflate state, and particularly the amount of pushing out the bead portion toward the rim flange is made small, and more concretely a displacement (d) of a point X changed from a deflate state to an inflate state is not more than 3 mm as measured at a section in the widthwise direction of the tire, wherein X is an arbitrary point on a carcass line located in a region of the bead portion outward from a contact region with a rim flange at the deflate state when the tire is mounted onto a recommended rim, whereby the contact pressure with the rim flange can be made small to considerably decrease the permanent set of the bead portion.
The position of the point X means an arbitrary point located on the carcass line within a range of xc2x120 mm centering on an intersect between the carcass line and a normal line drawn from the contact point with the rim flange to the carcass line at the deflate state of the tire. In other words, the point X existing within the above range means that the displacement d is not more than 3 mm.
And also, the displacement d means a displacing amount when the point X on the carcass line at the deflate state moves to a point Xxe2x80x2 at an inflate state (distance between point X and point Xxe2x80x2).
The term xe2x80x9cdeflate statexe2x80x9d used herein means that the tire is at a self-supportable state on the rim under no load after air is discharged from the inside of the tire or concretely at a state under an air pressure of 0.5-1.0 kgf/cm2. And also, the term xe2x80x9cinflate statexe2x80x9d used herein means that the tire is at a state of inflating at an air pressure corresponding to a maximum air pressure under no load.
Further, the term xe2x80x9cmaximum air pressurexe2x80x9d used herein means an air pressure corresponding to a maximum load of a single wheel having an approved size described in the following standard (maximum load capacity), and the term xe2x80x9crecommended rimxe2x80x9d used herein means a recommended rim (or approved rim) described in the following standard.
The standard is defined by Year Book of The Tire and Rim Association Inc. in USA, Standard Manual of The European Tire and Rim Technical Organization in Europe, and Year Book of JATMA in Japan, respectively.
Moreover, the term xe2x80x9ccarcass linexe2x80x9d used herein means a line passing through a thickness center of the carcass ply constituting the carcass body at a section of the tire in the widthwise direction. Concretely, when the carcass body is comprised of one ply, the carcass line is a line passing through the center of the cord embedded in the ply, while when the carcass body is comprised of two or more plies, the carcass line is a line passing through a thickness center of the laminated plies.
In FIG. 3 is shown an example of results measured on contact pressure to the rim flange in tires having different displacements d (i.e. pushing-out amount of bead portion) when the tire is changed from the deflate state to the inflate state.
As seen from FIG. 3, when the displacement d exceeds 3 mm, the contact pressure rapidly increases. In the usual tire, the displacement d at the inflate state is generally within a range of 4-6 mm.
In order to decrease the displacement d, it is favorable to satisfy a relation of R0 less than 2H, preferably R0 less than H when a radius of curvature of the carcass line at the point X is R0 and a section height of the tire is H at the deflate state.
In case of R0 less than H, the pushing-out amount of the bead portion can be zero or the bead portion can be deformed (recessed) in a direction opposite to the pushing-out direction, whereby the contact pressure to the rim flange can be more reduced.
In a still further preferable embodiment of the first aspect of the invention, a rubber layer controlling shearing strain is arranged between a bead filler and a bead portion reinforcing layer located at an outside of the tire, whereby shearing strain is suppressed at the turnup end portion of the carcass ply.
In this case, the rubber layer has a hardness middle between hardness of the bead filler and hardness of a sidewall rubber constituting a sidewall portion together with the bead filler. And also, a ratio of the hardness of the bead filler to the hardness of the sidewall rubber is not less than 1.4 times. Thus, the difference of stiffness between the bead filler and the sidewall rubber can be made small and also excessively interlaminar shearing strain is suppressed between the rubber layer and the bead portion reinforcing layer to avoid the occurrence of separation failure from an end portion of the bead portion reinforcing layer. Moreover, even when the number of the reinforcing layers is increased for preventing the deformation in the bead portion, stress does not concentrate in the vicinity of the end of such a reinforcing layer, so that the shearing strain resulting in the occurrence of separation failure is decreased.
When the thickness of the rubber layer is t2 and the thickness of the bead portion reinforcing layer is t1, it is favorable to satisfy a relation of 0.3t1xe2x89xa6t2xe2x89xa65t1. Thus, the deformation of the bead portion can be prevented without the concentration of shearing strain in the end portion of the bead portion reinforcing layer.
Furthermore, it is favorable that an end of the rubber layer is located at a position corresponding to an upper part of the bead core, preferably so as to contact with the turnup portion of the carcass ply and the other end thereof is extended along the bead portion reinforcing layer and protruded from an end of the reinforcing layer by 30 mm at maximum. Thus, it is possible to avoid the concentration of shearing strain in the turnup end of the carcass ply and the end of the reinforcing layer.
In the other preferable embodiment of the first aspect of the invention, a recess zone is formed in an outer profile of the bead portion located inward from a position of a maximum tire width in the radial direction of the tire at a radial section of the tire. Thus, the heat build-up of the bead portion during the running of the tire under loading is decreased by the formation of the recess zone, whereby the bead portion durability can be largely improved.
In the tire having the recess zone in its bead portion, a rubber gauge in a region ranging outward from a position corresponding to 1.8 times a maximum bead portion width located from a position of a nominal diameter of a rim flange in the radial direction of the tire to the position of the maximum tire width is substantially equal to a rubber gauge at the position of the maximum tire width. That is, the rubber gauge T (distance from the cord in the carcass ply to the outer profile of the tire) in a region ranging outward from a position corresponding to 1.8 times the maximum bead portion width located from the position of the nominal diameter of the rim flange in the radial direction of the tire to the position of the maximum tire width (rubber located at the outside of the carcass ply) is made substantially equal to the rubber gauge at the position of the maximum tire width (0.7-1.3 times the thickness at the position of the maximum tire width), while the rubber gauge in a region ranging inward from the position corresponding to 1.8 times the maximum bead portion width in the radial direction of the tire to a position of the bead core is gradually increased (or the depth of the recess zone is gradually decreased).
In general, the sidewall rubber is enough to have a rubber gauge required for preventing external injury in the vicinity of the position of the maximum tire width and is set to a value of rubber gauge thinner than that in the bead portion or the like. Even in the bead portion, it is desirable to make the rubber gauge thin considering only the heat build-up. On the other hand, the bead core is necessary to have a certain stiffness for fixing the tire onto the rim. If the rubber gauge is made thin up to the vicinity of the bead core likewise the case at the position of the maximum tire width, the bending deformation of the bead portion concentrates in the vicinity of the bead core to cause the concentration of strain in the rubber of the bead portion near to the bead core and hence there is caused a problem that crack is created at the outer surface of the tire in the vicinity of the bead core. However, such a problem is solved by the relation of rubber gauge as mentioned above in the invention.
Furthermore, it is favorable that the recess zone is arranged outward from an alienation point between the outer surface of the bead portion and the rim flange in the radial direction of the tire when the tire is mounted onto a recommended rim and stated at a maximum air pressure under a maximum load. If the recess zone is formed in a region of the bead portion contacting with the rim flange under loading, an amount of a space between the outer surface of the bead portion and the rim flange under an inflation of the air pressure is increased to increase the amount of the bending deformation under loading in the vicinity of such a region, which badly affects the bead portion durability. This problem is solved by arranging the recess zone outward from the alienation point between the outer surface of the bead portion and the rim flange under loading in the radial direction as mentioned above.
Moreover, when the width of the bead portion is violently decreased as compared with the maximum bead portion width in the region contacting with the rim flange under loading, the amount of space between the outer surface of the bead portion and the rim flange increases to increase the fall-down deformation of the bead portion. For this end, it is favorable that a thickness WP of the bead portion at the alienation point P between the outer surface of the bead portion and the rim flange at the inflation state of the maximum air pressure under the maximum load after the mounting onto the recommended rim satisfies a relation of WP/WMxe2x89xa70.9 when a width of the bead portion passing through a illustrated center of the bead core in parallel to a standard line of the bead portion thickness at the alienation point P is WM.
According to a second aspect of the invention, there is the provision of a method of manufacturing a pneumatic tire, which comprises subjecting a cylindrical carcass band to a forming treatment by bending each end portion of the band in at least one place in an axial direction of a green tire over a full circumference thereof inward or outward in a radial direction of the tire, arranging a ring-shaped bead core on an inside of the bent end portion, toroidally expanding the cylindrical carcass band while locking the bead core, and then joining a belt and a tread onto an outer peripheral side of the carcass band.
According to this method, the previously formed bent end portion is accurately formed in the required position of the cylindrical carcass band in correspondence with the peripheral shape and dimension of the bead core and then the bead core is inserted into the inside of the bent end portion, whereby the bent end portion can accurately be wound around the peripheral surface of the bead core even when the ply cord has a large elastic restoring force as in steel cord. And also, the winding posture can surely be maintained based on the plastic deformation through the previous forming, so that the fear of pulling-out the ply cords is sufficiently removed and also the separation failure of the turnup portion of the carcass ply from rubber can always and surely be prevented.
The bending formation of the end portion of the carcass band can be made inward or outward in the radial direction of the carcass band. In the former case, the end portion of the carcass band is turned up around the bead core from outside toward inside in the widthwise direction of the tile in a product tire. In the latter case, the end portion is turned up from inside toward outside in the widthwise direction of the tire.
Moreover, when there are plural bending positions in this method, the operation of the bending formation is carried out by bending each end portion of the cylindrical carcass band simultaneously at plural positions in the axial direction or in a given order. The simultaneous bending at plural positions is advantageous in view of the operation efficiency unless one of the positions affects the other position and is obstructed by the other position.
In a preferable embodiment of the second aspect of the invention, the bending at the each end portion of the cylindrical carcass band is carried out by relatively displacing a bending means and a cylindrical carcass band in the circumferential direction of the cylindrical carcass band. In this case, a bending means relatively displacing to a circumferential direction of a carcass band drum and hence a circumferential direction of a cylindrical shaped carcass band formed on the drum is merely added on the existing carcass band drum, and the cylindrical carcass band is subjected to the required bending work by putting the cylindrical carcass band from inner and outer circumferential sides thereof through the bending means, whereby the bent portion can surely be formed in the cylindrical carcass band being structurally soft with a less equipment cost as is expected.
In another preferable embodiment of the second aspect of the invention, the arrangement of the bead core at the inside of the bent end portion is carried out by subjecting the bent end portion to elastic deformation in an opening direction. When the cross sectional shape of the bent end portion is polygonal or the like and it is impossible to insert the bead core into the inside of the bent end portion at a state of bent formation, the insertion of the bead core is carried out at a state of open-deforming at an elastic zone, whereby the bead core can accurately be arranged in the required position and hence the proper winding of the bent end portion around the peripheral surface of the bead core can surely be realized.
In the other preferable embodiment of the second aspect of the invention, the bend end portion is subjected to stitching at a state of toroidally expanding the cylindrical carcass band while locking the bead core. In this case, the bend end portion can sufficiently be pressed onto the peripheral surface of the bead core by the stitching together with the pushing of air from both members at a state of sufficiently approaching the extending form of the carcass band to that of the green tire, whereby the expected effect can be more enhanced.
The bending formation of the end portion in the cylindrical carcass band can naturally be carried out even when the carcass band is comprised of organic fiber cords having a large elastic restoring force such as aromatic polyamide cords and the like, but the plastic deformation for the required bending formation can be carried out with a more higher accuracy when the carcass band is comprised of steel cords. And also, it is advantageous to develop the higher cord tenacity even when the plastic deformation is carried out.
According to a third aspect of the invention, there is the provision of an apparatus for bending a carcass band for use in the manufacture of the pneumatic tire, comprising a shaft-shaped member provided with an annular groove supporting an end portion of a cylindrical carcass band from an inner or outer circumferential side thereof, and a disc-shaped member located in a position corresponding to the annular groove and pushing the cylindrical carcass band into the annular groove.
In this bending apparatus, the cylindrical carcass band is putted between the shaft-shaped member and the disc-shaped member and pushed into the annular groove at a given force, so that the bending formation can simply, easily and accurately be carried out at a required position of the cylindrical carcass band in its axial direction by a simple and small apparatus independently separated from a carcass band drum forming the cylindrical carcass band. Such a bending formation can properly be carried out over a full circumference of the carcass band having a soft structure without disturbing the cord arrangement or the like in the carcass band, for example, by rotating at least one of the shaft-shaped member and the disc-shaped member to relatively move the bending apparatus to the cylindrical carcass band in the circumferential direction thereof, or by rotating the cylindrical carcass band to the bending apparatus.
In such a bending apparatus, when a plurality of annular grooves are formed on the shaft-shaped member at given intervals and disc-shaped members in accordance with the number of the annular grooves are arranged side by side in the same axial line, the bending formation can simultaneously be carried out in plural positions of the cylindrical carcass band separated at given intervals in its axial direction by the one action of the apparatus, whereby the working efficiency can largely be increased.
Moreover, the relative movement between the bending apparatus and the cylindrical carcass band in the circumferential direction can be carried out by connecting at least one of the cylindrical carcass band, shaft-shaped member and disc-shaped member to a rotation driving means, or by rotating at least one of the shaft-shaped member and the disc-shaped member on its axis and arranging a driving means for revolving both the members around the circumference of the cylindrical carcass band.
According to a fourth aspect of the invention, there is the provision of an apparatus for manufacturing a pneumatic tire, comprising a carcass band drum forming a cylindrical carcass band, a carcass band bending apparatus for subjecting an end portion of the cylindrical carcass band located on the carcass band drum to bending formation, a bead setter for arranging a ring-shaped bead core inside the bent end portion of the cylindrical carcass band, a bead lock for supporting the bead core arranged on the bend end portion from its inner peripheral side, and a shaping means for toroidally expanding the cylindrical carcass band.
According to this manufacturing apparatus, the above manufacturing method can easily be realized by adding the carcass band bending apparatus to the existing tire building apparatus, somewhat improving the bead setter and the like.
In this case, the shaping means can be added to the carcass band drum. Thus, the installation cost can be controlled to a low level by decreasing the number of the drums and also the step of transporting the cylindrical carcass band or the like can be made useless.
Alternatively, the shaping drum provided with the shaping means is disposed irrespectively of the carcass band drum and a transportation means for transporting the formed cylindrical carcass band into the shaping drum, and the carcass band bending apparatus and the bead setter can be added to the transportation means.